Operating mechanism for lift-ridges.



L. H. SHOEMAKEH. OPERMING MECHANISM Foa LIFT RwaEs.l

L. H. SHOEMAKER. AOPERATING MEcHANlsM FOR LIFT BRIDGES.

APPLICATION FILED MAILS, ISIS.

Patented Jan. 2,1917.

4 SHEETS- SHEET 2.

' 37 47 ffy/M4533@ /MMM L. H. SHOEIVIAKER. OPERATING NIECHANISIVI FOR LIFI BRIDGES.

APPLICATION FILED MAR. 9, 1916..

Patented Jan. 2,1917.

SHEETS-SHEET 3.

' WITNESSES INVENTB I. JW

L. H. SHOEMAKER. OPERATlNG NIECHANISM FOR LIFT BRIDGES.

4 SHEETS-SHEET 4.

mvtm'on M11-mesas LOUIS H. SHOEMAKER, OF PT'lSBURGI-I, PENNSYLVANIA OPERATING MECHANISM FOR LIFT-BRIDGES.

To ZZ whom t may concern.' l e it knownl that I, LOUIS H. SHOEMAKER, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny Operating Mechanisms for Lift-Bridges, lof

i the opposite ends of the lifting which the following is a specification.

y invention relates to the construction ofoperating mechanisms used in actuating oneto the other of the approaches at One object of this invention is to provide a lift bridge of improved construction and having novel means whereby the vertically moving liftin span of the bridge is raised to a height su `cient to clear vessels passing underl the bridge and is into position enabling traffic to pass over the bridge from one to the other of the approaches -at the ends of the bridge. other object of my invention is to provide a bridge lifting mechanism having a Iiovel arrangement of lifting cables whereby Y span of the ridge arev connected to a cable operating mechanism located in proximity to one end of the bridge. i

Another object of the invention is to provide a lift bridge having cable towers at the ends thereof and having improved means for leading the cables to the cable operating mechanism adjacent to one en of the bridge. of the invention is to for counterbalancing the lifting span of the for equalizing the tension on lifting span of the bridge.

urther object ofthe invention is to roe novel means for connecting the bridge the `cables; connecting the counter-balance `and lifting .mechanism therefor whereby the bridgeis positively actuated the bridge lowering operation.

A still further object of the sists in the provision of bridge lifting mech- Speci'cation of Letters Patent.

Vthe bridge arranged in accordance positively lowered invention con.-

Patented Jan., 2, 11.91%".

Application filed March 9, 1916. Serial No. 83,078.

operations and by which the tension on the cables forming part of the bridge lifting and lowering mechanism is equalized.

Still further objects of the invention consist in the provision of the novel combinations and arrangements of parts illustrated in the drawings, specifically pointed out in the appended claims, and more fully described hereinafter.

eferring now to the drawings forming part of this specification, Figurel 1 is a diagrammatic side elevation showing a bridge aving approaches and towers at the ends of shown in Fig. l. Fig. 3 is a diagrammatic side elevation showing the arrangement of the bridge operating cables Fig. 3, showing the end of the bridge having the operatmeral 2 designates the lifting span of the bridge,4 which is positioned between towers 3 and 4, and which is arranged to be raised and lowered from the position shown. by full i lines into and out ofthe position shown dotted in Fig. 1. The. towers as shown'` are framed into and form part of approaches 5 and 6 leading to the ends of the lifting span when the-lifting span is 'in lowered position (the position shown in full-lines in-.Fig 1). The lifting span 2 Acomprises two built up trusses each having a top chord 7 and bottransverse floor beams mi m and longitudinal v beams 11a, and on top lof the floor beams is a floor 12 made of wood as shown.

Each of the bridge approaches 5 and 6, of

which there is one at each end of the bridge, comprises two built up trusses, each Jtruss having a top chord 13, bottom vchord 14, vertical struts 15, and diagonal bracing 16, and the'wooden floor 17 for the approaches is carried on longitudinal floor beams 18a and transverse floor beams :v m between the trusses, the transverse .beams being supported at their ends by the bottom chords 14.

The towers 3 and 4, of which there is one at each end of the bridge, are formed of pairs of columns 19 and 2O which are con-l nected together by horizontal struts 21 and diagonal or cross bracing 22. The lower ends of the tower columns 19. 20, are framed into the ends of the trusses forming the approaches lto the lifting bridge span 2, and the columns 19, 19, and 20, 20, forming each tower are connected in pairs at their upper ends by lattice girders 19a, 20a.`

The construction of the lifting span of the bridge and approaches being known and not forming part ofthis invention, is not further described.

Adjustably secured by means of a turn-l buckle 24 to each corner of the left hand end of the lifting span 2 of the bridge, is a bridge lifting cable 25, these cables extending upwardly and after passing over one of the lifting cable-sheaves 26 at the top of the towerand engaging withaI gu'rdingvsheave 27, extend downwardly and pass under sheaves 28 rotatably mounted on the bottom chords 14 of the lifting span 2 of thel bridge. (See Figs. 2 and 5).. rlhe cables- 25 then extend across the bridge and after passing under one of the sheaves 29 at the other or right hand end of the lifting span 2 extend upwardly and over the pairs of sheaves 30 and 31 on the top of the tower 4, then downwardly-under one'of the sheaves 32 on the bottom chords 14 of the approach 4 and around the sheave a34, and are connected one to the under side of the drum 38 and one to the upper side of the drum 39- forming part of the cable actuating mecha- Fig. 1.

. .miopia nism, which is located beneath the approach 6 at the right hand end of the bridge. Also secured by means of a turnbuckle 24 to each corner of the lifting-span 2 at the left hand 'end of the bridge, is a lowering cable 35.

sheaves 28 mounted on the bottom chord 8 of the lifting span 2,- and, after extending across the bridge, one cable at each side thereof, the cables 35 passover sheaves 29,

'downwardly under sheaves 37 on the lower end of the columns 19 of the tower 4, then upwardly and around sheaves 32 on the bottom chord 14 ofthe approach 6, then extend to and around one of the sheaves 34, being connected, one cable to each of the winding drums 38 and 39. (See Figs. 2, 5 and 8).

Secured one to each corner of the right hand end of the lifting span 2 by means of' a turnbuckle 24 are lifting cables 41 for this end of the bridge, these cables extendingupwardly and passing around one of the sheaves 30 on top of the tower 4 at the right hand end of the bridge structure shown in The cables 41 then extend downwardly, pass around one of the sheaves 29 on the end of the lifting span 2 and then extend upwardly, and after passing over one of the pairs of sheaves 30 and 31 at the top of the tower, extend downwardly and around one of the sheaves 32, and from the sheaves 32 around a sheave 34, and are fastened one to the winding drum 38 and one to the drum 39 forming part of the cable operating mechanism. Also secured by means of a turnbuckle 24 to each corner of the lifting span 2 of the bridge at the right hand end thereof, are lowering cables 47 which extend downwardly, engage with a sheave 37, then extend upwardly and pass around one of the sheaves 29, then extend downwardly and pass around one ofthe sheaves 37, then pass around another of the sheaves 32 and around a sheave 34, and then extend one to each of the winding drums 38 and 39 of the cable operating mechanism to which *L ends of the cables 47 are fastened.

Pivotally connected to the frameworlrof the towers 3 and 4are counter-weighted, T- shaped levers 48 having a weight 48a adjustably secured' on one end thereof. The opposite end of the `levers. 48 has idler sheaves 49, 50, on the ends of the arm forming the head of the T-shaped levers, a pair of these sheaves 49, 50, engaging with each of the hoisting ropes 25, 41, and the counterweight 48'l causing the sheaves to equalize the tension put upon the ropes.` A similar counter-weight mechanism may be employed n the lowering ropes 35, 47, when found necessary or desirable.

buil i Opposite the right hand end of the bridge', r130 and floor beams of the apend of the bridge are the winding drums 38 and 39, both of which are mounted on a shaft 51 mounted in suitable bearings 52, 53, and having a spur gear wheel 54 on one end thereof. The spur wheel 54 is connected by pairs of reducing gears 55, 56, 57, 58, 59 and 60, to a spur pinion 61 on the end of the armature shaft 62 of the electric motor 63 by which the bridge raising and lowering cables are positively actuated in raising and lowering the bridge.

Rotatably mounte'd on top of and at the corner of each tower 3 and 4 is a set of one or more sheavewheels 64 for the counterbalance ropes or cables 65 and 66, 67 and 68. Secured by the loops in theV ends thereof to a pin or shaft 72 on the ends of the lifting span 2 of the bridge are the counter-weight cables 65, 66, 67, 68, which are arranged in pairs, these cables extending upwardly and then downwardly around the sheave wheels 64 and the loop formed in each cable passing around a sheave wheel 69, the sheave wheels 69 being pivotally connected by a lever 69a to the yoke 70 fastened to each end of the counter-weight 7l. has guiding sheave wheels 72 secured thereon to engage with one strand of the looped ropes or cables 65, 66, 67, 68, so as to keep the vertically extending strands of the cables in parallel relation and the same distance apart as the distance between the centers of the grooves in the series of sheave wheels 64. (See Fig. 7.)

The counter-weights 7l, one at each end of the bridge, to which the yokes are fastened, are conveniently arranged toeXtend across the width of the bridge at the end of the'approaches thereto when the lifting span 2 'is in lifted position and form barriers to beneath the ioor lifting span of the brid lifted position.

he operation of my improved apparatus will be readily understood. The motor 63 is caused to rotate in the required direction and actuate the lifting cables 25 and the lifting span 2 of the bridge being balanced by the counterbalance weights '7l the power required in lifting is materially reduced. As the lifting span 2 is raised the counterweights 7l descend and bar the passage of traflic at the ends of the bridge. approaches when the lifting span is in raised position. lVhen lowering the bridge span the lowering cables 35, 47, Vwhich are connected at o'ne end to the lifting' span 2 and at the ,other to the winding drums, 38, 39, pull the lifting span 2 downwardly s0 that the bridge is positively actuated in lowering the lifting span.

The advantages of my invention will be a5 appreciated by those skilled in the art. The

The yoke 70 also pf sets o f lowering cables whereby apparatus is simple, and isfreadily kept in repair. By leading the lifting cables and lowering cables from one end of the bridge across the length of the bridge and by connecting these cables to a common operating mechanism, the lifting' span ofthe bridge is maintained in horizontal position in the raising and lowering position. This arrangement of cables also avoids the necessity of providing girders or struts connecting the top of the tower at one end with the tower at the oppositel end of the bridge to take the stresses or strains set up in the towers when the cables extend from the top of the tower at one end to the top of the tower at the opposite end of the bridge. By leading the cables from the ,remote end of the bridge across the lifting'bridge span to the end of the bridge adjacent to the bridge lifting mechanism, the height of the towers necessary to use with4 a given clearance or head room is materially reduced.

Modifications in the construction and arrangement of the partsmay be made without departing from my invention as defined in the appended claims.

claim l. In a lift bridge, the combination with a vertically moving lifting' span, towers ai the ends of said lifting span, and a cable operating mechanism adjacent to one end of the lifting span, of a series of sets of lifting cables whereby said span is raised, said le operating mechanism and extending' upwardly and then downwardly over sheaves on the upper end of the bridge tower adjacent to said operating mechanism, one end of the cables in part of said sets of cables being adjustably secured to the adjacent end of the lifting span and part of said sets of cables leading across the lifting span and extending upwardly and then downwardlv.

over sheaves on the upper end of the other of the two towers, and having one end thereof adjustably secured to the other end of the lifting' span, and a series of sheaves rotatably mounted on the lifting span and the towers to travel of said sets of cables 'in raising' and lowering' the lifting' span.

2. ln a lift bridge, the combination with a vertically moving lifting span, towers at the ends of said lifting span, and a cable operating mechanism adjacent 'to one end of the lifting span, of a series of sets of lifting cables whereby said span is raised, a series said span 1s pos1t1 vely moved mto lowered position,

and extending upwardly and then downwardly over sheaves on the. upper end of the bridge tower mechanism, lone end of the cables in part guide and change the direction'of-' adjacent to said operatingof said sets of cables being adjustably 'secured to theadjacent end of the lifting span and part of said sets of `cables leading across the lifting span and extending upwardly and then downwardly over sheaves on theA 'operating mechanism adjacent to one end of said lifting span, of a` series of sets of cables whereby said .lifting span is raised and lowered, said cables being secured at one end to the cable operating mechanism and at least part thereof extending upwardly and then downwardly over rotatable sheaves on the upper end of the bridge tower adjacent to said operating mechanism,

one end of the cables in part of said sets of j cables being secured to the adjacent end of the lifting bridge span with at least part of said sets of cables leading across the lifting bridge span and, extending upwardly and then downwardly over sheaves on the upper end of the other of the two towers, and having one end thereof secured to the other end of the lifting bridge span, a series of sheaves rotatably mounted o-n the lifting span and the towers to guide and change the direction of travel of said sets of cables in raising and lowering the lifting span, and counter-weighted levers pivoted on said tower and having sheaves rotatably mounted `thereon adapted to engage the cables and equalize the tension thereof.

4. In a lift bridge, the combination with a vertically moving lifting span, towers at theends of said lifting span, and a cable operating mechanism adjacent to one 'end of the lifting span, of a series of sets vof lifting cables whereby said span is raised,

said lifting cables being secured at oneendf to said cable operating mechanism and eX- tending upwardly and then downwardly over sheaves on the upper end of the bridge tower adjacent to said operating mechanism, one end of the cables in partlof said sets of cables beingy secured to the y"adjacent end of the lifting' span and part of said sets of cables leading across the lifting span and extending upwardly and then downwardly ovenlsheaves on the upper end of the other ofthetwo towers, and havingone end there- "of secured to the other endv of the lifting span, and means on the lifting span and the towers to guide and change the direction of travel of said sets of cables in raising and lowering the lifting span.

5. In a lift bridge, the combination with a vertically moving lifting span, towers at the ends of said lifting span,.and a cable operating 'mechanism adjacent to one end of the lifting span, of a 'series of sets of lifting cables whereby said span is raised, a series of sets of. lowering cables whereby said span i`s positively Amoved into lowered position, said lifting cables. being secured at one end to said cable operating mechadownwardly over sheaves on the upper end of they bridge adjacent to said operating mechanism, one end of the cables in part of said sets of cables being secured to the ad jacent end of the lifting span and part of said sets of cables leading-across. the liftin-g span and extending upwardly 'and then downwardly over sheaves on the upper end of the other of the towers, said part of the sets of cables having one end lthereof secured to the other end of`the lifting span, and means on the lifting'span and towers to guide and change the direction of travel of .said sets of cables in raising and lowering the lifting span.

6. In a lift bridge, the combination with a verticallymoving lifting span, towers at the ends of said lifting span, and a cable operating mechanism adjacent to one end of saidlifting span, of a series of sets of cables whereby said lifting span is raised and lowered, said cables being secured at one end to the cable operating mechanism and at least part thereof extending /upwardly and then downwardly over rotatable sheaves `on the upper end of the bridge tower adjacent to said operating mechanism,

p one end of the cables in part of said sets of cables being secured to the adjacent end of the lifting bridge span with at least part of said sets of cables leading across the lifting bridge span and extending upwardly and then Ydownwardly over sheaves 011 the upper V4e/nd of the other of the two towers, and having one end thereof secured to the other end of the lifting bridge span, a series of sheaves rotatably mounted on the lifting span and the towers to guide and change the direction of travel of said sets of cables in raising and lowering the lifting span, and means on said tower arranged to engage with cables and equalize the tension on -said cables.

In testimony whereof I have hereunto set my hand. Y

LOUIS H. SHOEMAKER.

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Washington, D. G. 

